Tear strip opening means for containers



June 2, 1970 A. KOBZA TEAR STRIP OPENING MEANS FOR CONTAINERS Filed Aug. 12, 1968 -vv .2 no 1 4n ANTHONY V\OE ZA M Y /m/d.

PAT'J'INT AGENT 3,515,336 TEAR STRIP OPENING MEANS FOR CONTAINERS Anthony Kobza, Cap de la Madeleine, Quebec, Canada, assiguor to Consolidated Paper (Bahamas) Limited, Nassau, Bahamas Filed Aug. 12, 1968, Ser. No. 751,806 Int. Cl. B65d 17/20 US. Cl. 22966 1 Claim ABSTRACT OF THE DISCLOSURE The invention'relates to a bag or like container having a tear strip thereon to facilitate opening thereof, the tear strip comprising a solidified liquid composition directly and adhesively fixed to the container surface.

BACKGROUND OF THE INVENTION Field of the invention The invention is in the general field of tear strip opening means for bags or like containers.

Description of the prior art Tear strip opening means for containers are in very widespread use.

Frequently, the tear strip comprises a portion of the container wall itself defined by lines of weakness in the wall.

Also frequently, the tear strip comprises a tape, cord, thread, wire, or the like, formed of paper, fabric, plastic composition or other suitable material, adhesively or otherwise secured to the container wall.

SUMMARY OF THE INVENTION The present invention resides in a container having a tear strip fixed to a wall thereof, such strip consisting of of a solidified liquid composition having an inherent adhesive connection to the surface of said wall.

The invention also resides in a container forming process wherein there is applied directly to a surface of a travelling web of sheet material a continuous strip of a liquefied composition. The composition has an adhesive property with relation to the web surface and is hardenable to form a solidified strip thereon.

The provision of a tear strip consisting only of a solidified liquid adhesive results in a much simplified and less costly procedure as compared with prior art structures. Application of the strip is easy and convenient, as will subsequently appear, and a saving of material is effected in the case of applied strips.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of a bag in accordance with the invention,

FIG. 2 is a transverse section of the bag,

FIG. 3 is a diagrammatic perspective view of an apparatus for producing a bag in accordance with the invention, and

FIG. 4 is a perspective view of a modified portion of the apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the ensuing description, the container comprises a paper bag by way of example. The container may be formed of other types of tearable sheet material, such as cardboard, corrugated board, plastic composition, or the like.

Referring to FIGS. 1 and 2, the bag 10, as shown, comprises three plies 11 of paper although it may com- United States Patent O ice prise a single or any practical number of plies. The bag is of generally elongated tubular form and includes a pair of major side walls 12 joined by gusset sections 13, a bottom closure 14, and an open mouth 15 which, following packing of articles in the bag, is closed in the usual manner. It will be understood that the bag itself, as thus far described, is of conventional form and manufacture.

A strip 16 consisting of a hardened adhesive composition is fixed to the inside surface of the bag and extends throughout the entire longitudinal extent thereof, preferably, the strip is positioned on the inside surface of one of the side walls 12, as shown. A critical feature resides in the fact that the adhesive is applied directly to the bag surface in liquid form. In other words, the strip 16 is not preformed and includes no adhesive supporting or carry ing the body.

The strip 16 comprises a composition of solid plastic form at normal temperatures but which may be liquefied under the influence of heat. The composition is usually a conventional adhesive of self-hardening type whether it be of thermoplastic or of solvent evaporative or of selfhardening by oxidation nature. Thus, it may be an animal or vegetable glue or a thermoplastic resin, such as a polyethylene or polyvinyl butyral type. Desirably, the composition comprises an adhesive selected from the group of plastic based hot melt adhesives.

The thickness and width of the applied strip will be chosen to provide the required strength for a tear strip in the particular container or bag to which it is applied. For instance, on a conventional two-ply paper bag a strip of about thick and A" wide is quite satisfactory. It Will be apparent, however, that a simple experiment will determine the proper thickness and Width for severance of each specific container wall.

A pull tab 17 comprises a small section of bag. wall 12 overlying strip 16 and formed by, as shown, a U-shaped line of severance 18'. Tab 17 is located adjacent the bottom closure 14. The line of severance 18 extends through the strip 16 which constitutes an inner layer of the tab.

There is diagrammatically illustrated in FIG. 3 one manner of applying the strip 16 to a bag during its manufacture. Assuming that the bag is of 3-ply type, three webs 19, 20, 21 are drawn from paper supply rolls 22, 23, 24 over positioning rollers 25, 26, 27. Inner ply 19 is directed into a somewhat elevated, horizontal direction of movement by rollers 28, 29. During this direction of movement, the strip 16 is applied to the inner surface thereof by means of an applying device 30. Device 30 comprises a hopper 31 for feeding granules of plastic composition to an extruder device 32 driven at a speed proportional to that of web 19 :by means of an adjustable speed gear motor 33. The granules are fed to a heated nozzle post 34, where they are liquefied. The liquefied composition then flows through nozzle 35 onto the surface of travelling web 19. -It will be apparent that the thickness and width of the strip 16 may be controlled by the speed of flow of the composition through the nozzle and by the shape of the nozzle outlet. A strip of A; to inch in width is usually satisfactory.

The webs are then led over rollers 36 and thence over roller 37 where they are brought into interengagement. The composite web is then glued, tubed, cut to desired length, and provided with bottom closure to form bags in conventional manner.

FIG. 4 illustrates another convenient manner of applying the strip 16 wherein the liquefied composition is contained in a vessel 38. A driven roller 39 has a portion extending into the bath and the resulting liquid film adhering to the peripheral surface thereof is transferred by a transfer roller 40 to an applying roller 41 in surface engagement with the web 19.

I claim:

'1. In combination with a bag comprising a tubular wall of multi-ply paper sheets having a bottom closure at one end and a mouth at the other end, means for producing a line, of severance in said wall comprising a tear strip on the inner surface of the inner paper sheet of said wall and extending continuously from end to end thereof, said strip consisting of a solidified liquid adhesive composition having one of its longitudinal surfaces in direct adhesive engagement with said wall surface from end to end thereof and its remaining longitudinal surface exposed, and a pull tab comprising a partially severed section of said Wall and said strip, said tab being located in 5/1959 Voege et a1. 229-66 12/1965 Mueller 229-66 DAVID M. BOCKENEK, Primary Examiner US. Cl. X.R. 2295l 

